1. System Requirements High-level Software Requirements Software Qualification Test Software Architecture Software Integration Test Source Code (SC) Software Unit Test Executable Object Code (EOC) Low-level Software Requirements DO-178B and V-Model Summary (1) System Qualification Test
2. DO-178B and V-Model Summary (2) SQA ensures process transition criteria are satisfied [SQAR]. Ensure independence in multiple development activities. Ensure test coverage of detailed code structure is achieved [SVR]. Ensure architecture and low-level requirements are compatible with target computer. Ensure high-level requirements are compatible with target computer. Levels A, B SQA ensures development standards are followed. Provide SCM traceability between baselines [SCI, SCMR]. Produce coding standard [SCS]. Ensure source-code conforms to standard [SCS], is accurate and consistent, and complies with architecture and low-level requirements. Ensure test coverage of basic code structure is achieved [SVR]. Ensure source-code is traceable to low-level requirements. Produce design standard [SDS]. Ensure architecture and low-level requirements [DD] conform to standard [SDS], are accurate and consistent, and comply with high-level requirements. Ensure [EOC] is compliant and robust with respect to low-level requirements [SVCP, SVR]. Ensure test coverage of low-level requirements is achieved [SVR]. Ensure low-level requirements are traceable to high level requirements. Produce requirements standard [SRS]. Ensure high-level requirements [SRD] conform to standard [SRS]. Levels A, B, C Produce plans [SDP, SVP, SCMP, SQAP, TQP]. SQA ensures plans are followed [SQAR]. Provide SCM identification, change control and archive [SCI, SECI, SCMR, PR]. Ensure independence in SQA activities. Liaise with the certification authority [PSAC, SAS, SCI]. Produce source-code [SC]. Produce and integrate executable object code [EOC]. Develop software architecture and low-level requirements [DD]. Ensure partitioning integrity. Develop high-level software requirements. Ensure high-level requirements are defined [SRD], accurate and traceable. Ensure executable [EOC] is compliant and robust with respect to high-level requirements [SVCP, SVR]. Ensure test coverage of high-level requirements is achieved [SVR]. Levels A, B, C, D Other Processes Coding and Verification Design and Verification Requirements and Verification
Notes de l'éditeur
DO-178B objectives imply rather than mandate explicitly a V-Model. Likewise, other standards (e.g. IEEE 12207, IEC 61508, ISO 26262) are V-Model based. As the DO-178B assurance level becomes more onerous, evidence from deeper within the V-Model is required. All levels (A through to D) demand a lot of assurance for Requirements, but only levels A and B need detailed SC assurance.
Summary of Tables in Annex A of DO-178B. Note, objectives applying to all four levels are concentrated on Requirements processes – in fact, no SC assurance is required for Level D! This “requirements-based” theme is reflected also in the body of DO-178B (refer 6.4.2 and 6.4.3), and is taught by DO-178B gurus (e.g. Mike DeWalt). Concentrating effort on code based assurance to the exclusion of requirements assurance is a common but gross misinterpretation and misrepresentation of DO-178B. Levels A and B require significantly more effort because, code (SC and EOC) and the coding processes require additional verification, and independent satisfaction of multiple objectives is required.
![DO-178B and V-Model Summary (2) SQA ensures process transition criteria are satisfied [SQAR]. Ensure independence in multiple development activities. Ensure test coverage of detailed code structure is achieved [SVR]. Ensure architecture and low-level requirements are compatible with target computer. Ensure high-level requirements are compatible with target computer. Levels A, B SQA ensures development standards are followed. Provide SCM traceability between baselines [SCI, SCMR]. Produce coding standard [SCS]. Ensure source-code conforms to standard [SCS], is accurate and consistent, and complies with architecture and low-level requirements. Ensure test coverage of basic code structure is achieved [SVR]. Ensure source-code is traceable to low-level requirements. Produce design standard [SDS]. Ensure architecture and low-level requirements [DD] conform to standard [SDS], are accurate and consistent, and comply with high-level requirements. Ensure [EOC] is compliant and robust with respect to low-level requirements [SVCP, SVR]. Ensure test coverage of low-level requirements is achieved [SVR]. Ensure low-level requirements are traceable to high level requirements. Produce requirements standard [SRS]. Ensure high-level requirements [SRD] conform to standard [SRS]. Levels A, B, C Produce plans [SDP, SVP, SCMP, SQAP, TQP]. SQA ensures plans are followed [SQAR]. Provide SCM identification, change control and archive [SCI, SECI, SCMR, PR]. Ensure independence in SQA activities. Liaise with the certification authority [PSAC, SAS, SCI]. Produce source-code [SC]. Produce and integrate executable object code [EOC]. Develop software architecture and low-level requirements [DD]. Ensure partitioning integrity. Develop high-level software requirements. Ensure high-level requirements are defined [SRD], accurate and traceable. Ensure executable [EOC] is compliant and robust with respect to high-level requirements [SVCP, SVR]. Ensure test coverage of high-level requirements is achieved [SVR]. Levels A, B, C, D Other Processes Coding and Verification Design and Verification Requirements and Verification](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)